Retinoids block phenotypic cell transformation produced by sarcoma growth factor

Print
Published on Wednesday, 17 February 2021

Abstract

MURINE SARCOMA VIRUS (MSV)-transformed cells lack available receptors for epidermal growth factor (EGF).

We have shown that this altered phenotype is the result of the endogenous production of growth factors by the MSV-trans-formed cells themselves. The major activity, isolated and purified from transformed cells, has been found in a 12,000-molecular weight peak and competed with EOF in an EGF-receptor-binding assay.

This growth factor, called sarcoma growth factor (SGF), stimulates cell division, causes normal cells to grow in soft agar and produces rapid, reversible morphological transformation of cells in monolayer culture. There is no evidence that SGF acts as a complete carcinogen, producing permanent cell transformation; its properties resemble classical chemical promoters of carcinogenesis, like 12-O-tetradecanoylphorbol-13-acetate (TPA), the highly active component of croton oil.

Whereas TPA is an exogenous plant derivative acting on an animal or a cell, SGF is an endogenous, virally induced growth promoter. In this respect it is interesting that retinoids (vitamin A and synthetic analogues) block the action in vivo of exogenous and endogenous promoters, preventing carcinogens from producing new tumours, but do not reverse the growth of many established tumours.

Retinoids prevent cancer of the lung, skin, bladder and mammary gland in experimental animals, block cell transformation induced by chemicals and radiation in culture, and reverse the anchorage-independent growth of transformed mouse fibroblasts.

If SGF is part of the natural tumour-promoting system and retinoids are part of the natural defence against that system, then one should be able to demonstrate a direct antagonism in cell culture. This, report establishes that this happens.

 

About this publication.

See also:

- Official Web Site: The Di Bella Method;


 


- The Di Bella Method (A Fixed Part - All-Trans Retinoic Acid, Analogues and/or Derivatives - Approximately 60mg per day orally: 40mg per day Beta-Carotene/β-Carotene, 10mg per day ATRA and 10mg per day Axerophthol palmitate);

- All-Trans-Retinoic Acid (ATRA - analogues and/or derivatives) - In vitro, review and in vivo publications;

- Solution of retinoids in vitamin E in the Di Bella Method biological multitherapy;

- The Di Bella Method (A Fixed Part - Alpha tocopheryl acetate/Vitamin E, approximately 20 grams per day orally);

- Cancer and Vitamin E (analogues and/or derivatives) and cancer - In vitro, review and in vivo publications;

- The Di Bella Method (A Fixed Part - Bromocriptine and/or Cabergoline);

- The Di Bella Method (A Fixed Part - Cyclophosphamide 50mg tablets and/or Hydroxyurea 500mg tablets, one or two per day);

- The Di Bella Method (A Fixed Part - Somatostatin, Octreotide, Sandostatin LAR, analogues and/or derivatives);

- Somatostatin in oncology, the overlooked evidences - In vitro, review and in vivo publications;

- Publication, 2018 Jul: Over-Expression of GH/GHR in Breast Cancer and Oncosuppressor Role of Somatostatin as a Physiological Inhibitor (from Di Bella's Foundation);

- Publication, 2018 Sep: The over-expression of GH/GHR in tumour tissues with respect to healthy ones confirms its oncogenic role and the consequent oncosuppressor role of its physiological inhibitor, somatostatin: a review of the literature (from Di Bella's Foundation);

- Publication, 2019 Aug: The Entrapment of Somatostatin in a Lipid Formulation: Retarded Release and Free Radical Reactivity (from Di Bella's Foundation);

- Publication, 2019 Sep: Effects of Somatostatin and Vitamin C on the Fatty Acid Profile of Breast Cancer Cell Membranes (from Di Bella's Foundation);

- Publication, 2019 Sep: Effects of somatostatin, curcumin, and quercetin on the fatty acid profile of breast cancer cell membranes (from Di Bella's Foundation);

- Publication, 2020 Sep: Two neuroendocrine G protein-coupled receptor molecules, somatostatin and melatonin: Physiology of signal transduction and therapeutic perspectives (from Di Bella's Foundation);


 


- Congenital fibrosarcoma in complete remission with Somatostatin, Retinoids, Vitamin D3, Vitamin E, Vitamin C, Melatonin, Calcium, Chondroitin sulfate associated with low doses of Cyclophosphamide in a 14-year Follow Up;

- Somatostatin, retinoids, melatonin, vitamin D, bromocriptine, and cyclophosphamide in advanced non-small-cell lung cancer patients with low performance status;

- Somatostatin, retinoids, melatonin, vitamin D, bromocriptine, and cyclophosphamide in chemotherapy-pretreated patients with advanced lung adenocarcinoma and low performance status;

- Observations on the Report of a case of pulmonary adenocarcinoma with lymph node, hepatic and osseus metastasis;

- The Synergism of Somatostatin, Melatonin, Vitamins Prolactin and Estrogen Inhibitors Increased Survival, Objective Response and Performance Status In 297 Cases of Breast Cancer;

- Complete objective response, stable for 5 years, with the Di Bella Method, of multiple-metastatic carcinoma of the breast;

- Evaluation of the safety and efficacy of the first-line treatment with somatostatin combined with melatonin, retinoids, vitamin D3, and low doses of cyclophosphamide in 20 cases of breast cancer: a preliminary report;

- The Di Bella Method (DBM) improved survival, objective response and performance status in a retrospective observational clinical study on 122 cases of breast cancer;

- Complete objective response to biological therapy of plurifocal breast carcinoma.